This invention relates generally to lift mechanisms and, more particularly, to electrical control systems for controlling the operation of stairway wheelchair lifts operable to transport handicapped people in ascending and descending directions along a stairway.
Stairway wheelchair lifts, that operate to carry wheelchair-bound passengers in ascending and descending directions along a stairway, are particularly well suited for use in applications, such as in smaller multi-story structures having four or fewer floors, wherein elevators are impractical. In particular, stairway wheelchair lifts are able to utilize existing stairways and, thus, avoid the need for separate, special, architectural consideration. However, because stairway wheelchair lifts are called upon to operate within the confines of existing stairways, and because such stairways can differ considerably from structure to structure, it is desirable that stairway wheelchair lifts be readily adaptable for installation within stairways which each impose a unique set of physical and operational constraints.
To maximize both utility and safety, it is desirable that stairway wheelchair lifts provide operation which is, to at least some extent, dictated by the physical constraints imposed by the stairway itself. For example, it may desirable to reduce the speed of the lift at times in order to avoid potentially hazardous accelerations as the lift turns sharp corners. In addition, overall utility is increased and greatest economy is obtained, if a single basic system can be easily adapted for use in structures having two, three or four stories.
Although the mechanical features of a stairway wheelchair lift greatly influence the overall flexibility of the lift, an electrical control system for operating such a lift can further affect overall system flexibility, economy and effectiveness. Those electrical control systems which provide maximum system flexibility in combination with minimum complexity, particularly with regard to permanent wiring within the stairway, are to be preferred.
In view of the foregoing, it is a general object of the present invention to provide a new and improved electrical control system for stairway wheelchair lifts.
It is a more specific object of the present invention to provide a new and improved electrical control system for stairway wheelchair lifts which is readily adaptable for use with stairway wheelchair lifts operating under various unique constraints imposed by a particular stairway.
It is a still more specific object of the present invention to provide a new and improved electrical control system for stairway wheelchair lifts which promotes overall system flexibility and permits the use of a single basic system in a variety of different stairways and situations.